Similar plans are already the subject of a two-year feasibility study agreed by the Jordanians, Israelis and Palestinians in a rare example of cross-border Middle East co-operation.

But the Jordanians have decided they cannot wait any longer. "Jordan will start with the first phase with the help of donor countries and private investors," its minister for water, General Maysoun Zu'bi, said this week.

But environmentalists said the two years allotted to the feasibility study were already too short for a proper assessment of the risks posed to the Dead Sea's unique ecology. Environmentalists are concerned that the mixing of two different types of salt-water might have serious ecological consequences, including a build-up of algae.